Method for the covering of moldable articles (in particular, the heels and soles of shoes) and mold for application of said method

ABSTRACT

A method for the partial or total covering of any moldable article (particularly suitable for the heel and soles of shoes), characterized by the fact that the said covering is carried out during the molding, by placing the covering, which has previously been cut out or sliced off in the desired shape, against the surface of the mold, in areas corresponding to those of the molded piece that have to be covered, the limits of the said areas having been at least partly marked by protruding parts located on the walls of the mold itself.

United States Patent Giannini [54] METHOD FOR THE COVERING OF MOLDABLEARTICLES (IN PARTICULAR, THE HEELS AND SOLES OF SHOES) AND MOLD FORAPPLICATION OF SAID METHOD [72] Inventor: Michele Giannini, Viahnbriani, 81,

Barletta, Italy 22 Filed: July 14, 1969 211 Appl. No.: 841,536

[ Foreign Application Priority Data July 12, 1968 Italy ..916/68 Feb.17, 1969 Italy ..905/69 [52] US. Cl ..264/219, 18/42 H, 156/79, 264/244[51] Int. Cl. ..A43d 65/00 [58] Field of Search ..156/196, 380, 500, 79,295; 51/240, 291; l2/49.1; 264/244, 275, 219, 277, 278, 261, 275;249/91; 18/30 US, 42 H [56] References Cited UNITED STATES PATENTSGrimmeisem. 4

[451 Dec. 12, 1972 831,151 Gaeth.:. ..51/290 X 10/ 1906 1,747,629 2/1930Hansen ..51/290 UX 1,860,158 5/1932 Peterson ..156/196 UX 2,006,3777/1935 Wheeler ..156/196 X 3,513,050 5/1970 Samuels et a1 ..156/196FOREIGN PATENTS OR APPLICATIONS 944,545 1 2/ 1963 Great Britain 1 56/295 Primary Examiner-Benjamin A. Borchelt Assistant Examiner-G. E.Montone Attorney-Edwin E. Greigg ABSTRACT A method for the partial ortotal covering of. any moldable article (particularly suitable for theheel and soles of shoes), characterized by the fact that the saidcovering is carried out during the molding, by placing the covering,which has previously been cut out or sliced off in the desired shape,against the surface of .the mold, in areas corresponding to those of themolded piece that have to be covered, the limits of the said areashaving been at least partly marked by protruding parts located on thewalls of the mold itself.

PATENTEDnEm 1 12 3,705,934

SHEET 1 OF 2 FUENTES DEC 12 [9?2 SHEET 2 0F 2 1 METHOD FOR THE COVERINGOF MOLDABLE ARTICLES (IN PARTICULAR, THE HEELS AND SOLES OF SHOES) ANDMOLD FOR APPLICATION OF SAID METHOD The object of the present inventionis a new, simple, quick and economical method for the partial or totalcovering of any moldable article.

This method is particularly useful for the total or partial covering ofthe heels or soles of shoes produced by stamping, injection-molding, orany other means. Up to now such covering has been performed by glueingthe covering layer to the surface to be covered, at the cost ofconsiderable time and labor.

The method in accordance with the invention achieves such covering byplacing the piece constituting the covering, which has previously beencut out or sliced off or obtained by any other means whatever) in thedesired shape, inside the mold, laying it against the surfaces ofthe'latter in position corresponding to the parts of the article to becovered. The heel or sole is then made by stamping, injection-molding,or by any other method. The material inserted in the mold will then takeshape inside the covering, and, by pressing itself and thecovering'against the surfaces of the mold, will become anchored andwelded to the covering, at the same time taking on its permanent shapeand being permanently covered.

By this method it is easy to perform the partial or total covering ofthe heel of a shoe, with or without the addition of a filler orreinforcing material of any suitable kind. It is also possible toreproduce limitations, by

FIG. 4 represents a medianlongitudinal cross-section of the mold for theheel, the sole, and the covering, before the material has been injected.

FIG. 5 represents the horizontal cross-section in accordance with C-C inFIG. 4.

FIG. 6 represents the transversal cross-section of the mold in the areaof the heel, corresponding to D-D in FIG. 4, and

FIG. 7 is a perspective view of a portion of a mold which has beenslotted to receive a blade and holding means therefor. 4

The example that follows, described with reference to a process forforming the heel or sole of a shoe by injection-molding, is not meant asa limitation, but only means of this latest, simple, speedy andeconomical technique, of classic styles of covering, and to obtain neweffects, so far never achieved with the same case and perfection.Indeed-still taking as our example the covering of the heel of a shoe,since the heel, at the moment when it is covered, is a plasticmaterial-the said plastic penetrates into all the cracks and hollows itencounters, and this makes it possible to obtain coverings withimitation frets and various ornamental designs or motifs, which look asthough they have been printed, in two or more colors, on the coveringitself.

Apart from this color-effect, it is possible to exploit the contrastcaused by reflected light between the surfaces where the plasticmaterial shows and the surfaces that are covered. This is done by anappropriate choice of material for the covering and of the type offinish that can be applied to the surfaces of the mold.

It would be practically impossible to obtain these effects bytraditional methods of covering.

If the material with which it is intended .to do the covering is suchthat it cannot be welded to the material used for molding the article,the covering may be coated with a suitable glue, or similar substance,before being placed in the mold.

The attached drawings are diagrams of some of the ways of performing theprocess in accordance with the presentinvention, as follows:

FIG. 1 represents a median longitudinal cross-section of the mold andthe covering, before any material has been injected.

FIG. 2 represents the horizontal cross-section corresponding to A--A inFIG. 1.

FIG. 3 represents the transversal cross-section corresponding to B --Bin FIG. 1.

as an illustration, being generally valid for any other process forforming the said heel or sole, such as stamping, by means of theself-expandingof the material used, etc.

As will be seen from the figures, 5 indicates the internal surface ofthe covering 6, which will come into direct contact with the plasticmaterial to be injected through the aperture 10 within the cavity'4 ofthe mold (FIG. 1). The space 7 (FIG. 4) is .designed to receive theplastic material forming the bottom of the heel and the space 8 FIG. 4)is designedto receive the part of the plastic material forming theartificial sole running along the upper rim of the heel.

11 indicates those parts of the mold known as .rings, which reproducethe side surfaces of the heel andthe sole.

The pins 9 (FIGS. 4,5 and 6) mark the edge of the area to whichthe'covering 6 is to be fixed-so that the latter will not move wheninjection takes place. These support-pins 9 are not necessary in FIGS.1, 2 and 3, because the. covering 6 rests, on one side, on the bottom ofthe mold 12 that reproduces the heel and the lower surface of the soleand, on the other, against that part 13 of the mold that reproduces theupper surface of the sole.

In the examples given in FIGS. 4, 5 and 6, however, in which thecovering 6 is suspended between the space 7 and the space 8, it isnecessary to fix the covering 6 by means of protruding edge-markers,which are the support pins 9.

The present invention also offers another means for determining theposition of the covering 6 against the wall of the mold 12, and thismeans consists of embedding in the wall of the mold 12 a very thin bladeof metal, which protrudes from the surface of the mold, thus forming aframe 14 designed to contain and hold the perimeter edges of thecovering 6. I

Obviously, when the metal blade 14 is used, the pins 9 are not used andvice versa.

- The process by which the protruding blades 14 are embedded in theinside wall of the mold, by an economical, convenient and efficientmethod, will be hereinafter described.

The method so far described can be applied in all cases in which thecovering 6 is such that it can be inserted in the mold before the latteris completely closed, and before injection of the plastic materialforming the article to be covered. This material, which has to beinjected into the mold through at least one aperture 10, whose positionis chosen in such a way that the said material will flow against surface5 of the covering 6, so that the latter isbrought into contact with thesurface of the piece that it is intended to cover. The inserts 14 forholding in place the covering 6 are made of thin blades of metal, andare embedded in the walls of the mold 11 and 12), so as to intersect thesurfaces of the latter and to protrude from them so as to partly ortotally mark out those parts of the surface of the mold whose shapecorresponds exactly to the covering to be applied to the articleconcerned.

These blades are applied in such a way as to protrude, preferably to thesame extent, from the surfaces of the mold, thus forming a sort of frameor enclosing edge 14 and totally or partially marking the limits of thesurface of the mold corresponding to the areas of the article to becovered-such as the heel of a shoe, for example. The amount the blades14 protruding from the surface of the mold may vary to a considerableextent, depending on the type and thickness of the material used for thecovering and the thickness of the. article being molded in the area thatis to be covered. I

The thickness of the blades is also subject to considerable variation;but it should be borne in mind that it is nearly always an advantage touse very thin blades, so that the jointbetween the covering and thefinished piece does not show. The thickness of the blades shouldpreferably be kept within a few tenths of a millimeter. A furtherpurpose of the present invention is to describe a simple and accuratemethod of inserting the thin blades in the inside of the molds-for itwould appear hardly possible to insert thin blades no more than a fewtenths of a millimeter thick to a depth of 4 or mm, making acorrespondingly small slit in the inside wall of the mold with the aidof an electric etcher, or any other type of cutting instrument ormachine. To obviate .this difficulty, therefore, the present inventionproposes the following procedure:

a. Cavities 100 are made in the molds, preferably with a flat base andcylindrical walls, of which at least one should follow the line alongwhich it is intended to insert the blade. The cavities are made by meansof a cutter, whose axis of rotation is oriented with the generatinglines of the cylinder, whose directrix is the line itself, and whosegenerating lines are thestraight lines produced through the line andparallel to the direction considered most suitable for the extraction ofthe molded article and, at the same time, for keeping the covering inthe desired position during molding operations.

b. The blade to be inserted is shaped in such a way that it can beexactly superimposed on the cylindrical wall obtained in the waydescribed in a). This shaping can be done, for example, in accordancewith the known method for making light-steel, hollow punches for makingparts for shoes, by executing a flat shape in sheet-metal or with asuitable type of cardboard, thus reproducing on one of its edges thecylindrical wall section, with one surface perpendicular to itsgenerating lines. This shape is obtained easily by copying, directlyfrom the cavity, the perimeter of the latters base and using thecorresponding part for the aforementioned section.

c. The blade 14 shaped in this manner is placed, parallel to theaforementioned cylinder, inside the cavity 100 and against the former,so that the outer corners t a. I of the blade are exactly superimposedon the outer corners of the cylinder itself. I

d. A piece 101 is then made to insert in the cavity 100 made in the wallof the mold, in which the blade 14, as described in (c), has alreadybeenlaid, employing a cutter or pantograph, or the like, in such a way thatthe said piece 101 may be properly inserted with a minimum of play inthe cavity 100 itself, which already contains the blade 14 in thedesired position, and so that this piece can if necessary be fixed bycertain means (such as screws, bolts, pins etc.) accessible from theoutside of the mold.

e. The height of the piece 101 and of the blade 14 Should, asa generalrule, be greater than or equal'to that of the cavity 100. When thisoperation has been completed, the next step is to machine-the mold,after which the blade 14 will be at the same level as the surface of themold. In order to have the blade 14 protruding again, it willbenecessary to extract once more both blade 14 and the piece 101 inserted.The blade must then be corrected, readjusting its level and then cuttinga new blade of the same shape, using the first one as a model, butmaking the blade higher by'the amount it is desired that it shouldprotrude from the surface of the mold; the blade is reshaped as in thefirst instance and again inserted in the cavity in the mold, with thebase still coinciding with that of the cavity.

. Another version of the operation would be to shift the blade relativeto the inserted piece by the extent to which it is desired that itprotrude from the surface of the mold, fixing it to the piece in thatposition and again inserting the whole thing in the cavity. All theabovedescribed operations can be performed in reverse order, firstmaking the piece to be inserted in-the mold, then shaping'and placingthe blade on it, and lastly making in the mold a'cavity suitable forreceiving the said piece with the'blade fixed to it. The said cavity maybe made in two different ways: either by cutting into the mold withsuitable copying apparatus a cavity having cylindrical walls to fit,with the minimum play, the cylindrical walls of the piece to beinserted, oriented in such a way that the blade fitted to it remains inthe desired position in the finished mold; orelse, by scribing on themold, perpendicular to the direction of the generating lines of thecylinder of the piece, the crosssection of the piece with the bladefixed to it, with a surface perpendicular to the cylindrical wallsthemselves (base of piece), orientated in such a way that the bladeends'up in the right position in the mold.

Having done this, it will be possible to cut awayall the material of themold within the area marked out, including the markings themselves. Inthe special case of the blades to be inserted being flat, because thelines along which they have to be inserted are straight, or else becausethere are straight lines contained within the surfaces themselves alongwhich it is desired to insert the blade, the said blades, being alreadyflat, do not have to be shaped. The method described may in such a casebe carried out with the following variations. In this case, the axis ofrotation of the cutter employed to make the cavity need not necessarilybe parallel to the surface on which the blade is to be placed, but mayalso be perpendicular to it. If the aforementioned cavity is made insuch a way that the piece to be inserted can be inserted so that itssurfaces rub slightly against the walls of the cavity in a directionparallel to the surface into which the blade is to be inserted, but atleast in a perpendicular direction, it will be possible to carry out thetwo following variants of the operation:

f. A piece is made that is an exact copy of the cavity, while keepingthe same, essential degree of play, the blade not having yet been placedin the desired position. The blade is then placed in the desiredposition, and the piece is inserted in the cavity against the blade incontact with the latter. The piece is fixed in the cavity with suitablebolts or screws, which press it against the blade, after which any partof the piece that protrudes too far from the cavity, becauseof the extrathickness due to the presence of the blade,is cut or filed away.

g. In the cavity, in the area in which the blade is to be placed, thereis put any piece of blade of the same thickness as the blade that willeventually be inserted, this blade being designed only to supply theright degree of thickness, as a temporary measure. The piece or metalinsert is then made, as stated in (f) above, after which the mold ismachined and finished. When the mold is finished, the temporary piece ofblade is removed and the final version ofthe blade inserted,

cutting it so that it protrudes from the surfaces of the mold to theextent desired.

According to another variant, which can be applied if the blade isarranged along straight or flat lines, the blade, or any piece of blade,which serves to supply the necessary thickness, is placed on the piecefrom which it is intended to make the insert to be set in the cavity;this is done after suitable smoothing of the first surface, which willbe'assumed to be the surface in contact with the blade, when the latteris in the desired position. The piece to be inserted in the cavity isthen made from the piece so arranged and orientated.

The metal piece or insert, with the blade (or temporary blade) attached,is then inserted in the cavity in the mold. The machining of the mold isthen completed, and finally, the first blade (or the temporary piece ofblade) is replaced by the final blade, cut in such a way that itprotrudes from the surfaces of the mold to the desired extent.

In certain cases, along any closed or open lines along which it isdesired to insert blades, it is possible to insert a piece made fromsuitable sheet-metal (of appropriate thickness), shaped like the bladesthemselves, as previously described, and to insert this piece in thecavities made in the molds. Such a piece may be considered and appliedas equivalent for all practical purposes to pieces copied with cuttersor pantographs, (or, in cases in which it is possible and convenient, itcan be adapted manually with a file or flexible, portable cutter).

In this case, the general method described is varied in the followingmanner:

Cavities are made in the mold by cutting along the lines along which itis intended to place the blades in such a way as to touch the linesthemselves at points, with a cutter whose diameter is equal to thethickness of the blade plus that of the sheet-metal from which it isintended to shape the metal insert, and plus any play necessary forinserting in the cavities made the blades and inserts.

The shaping of the blade is easily done with the machinery normally usedfor making hollow punches for cutting materials for shoes. The rest ofthe operation is carried out as previously described. In special cases,it will be possible to use a suitable sheet, metal, shaping it to thelines around which it is desired to place the blades, as follows: I

h. By cutting, if necessary, along the lines along which it is desiredto place the blades with a suitable cutter, inorder to obtain the partsof the cylinders that have as their directrixes the lines themselves.

i. By placing along the lines themselves, along which the blades, heldin place by some suitable means, have been arranged, the sheet-metal,and gradually shaping it along and on the lines themselves, as well asgradually fixing it, if necessary to the walls of the cylinders,

whose directrixes are the lines and to the blades themselves, fixed inbetween with suitable bolts or screws.

1. In many cases, in which the sheet-metal is so arranged as to be nextto the surfaces of detached or detachable pieces of the mold, ifnecessary, on the sheet-metal, there may afterwards be performed thenecessary cutting and filing operation to adapt the piece on which thesheet-metal has been placed.

What is claimed is:

v1. A method of making the heel of a shoe comprising the steps of v A.providing a mold having a cavity configured to produce the heel andincluding a curved vertically extending wall,

B. inserting and fixing horizontally extending very thin blades in thecurved vertically extending wall of the cavity, said blades followingthe curvature of the wall being vertically spaced and projecting intothe cavity a small amount,

C. placing a preformed covering material against the curved verticallyextending wall of the cavity and abutting a continuous extent of boththe upper edge and the lower edge of the material against the blades soas to be held in position thereby,

D. injecting a plastic material into the cavity of the mold to press thepreformed covering material against the wall of the mold and to bondwith the plastic,

E. permitting the plastic material to harden and bond to the preformedcover and F. removing the injected molded heel with its cover from themold.

2. The method of claim 1, in which the step of inserting and fixing thevery thin blades in the mold includes A. forming a groove in thevertically extending wall of the cavity,

B. placing a said blade in the groove and against the bottom side wallof the groove and C. snugly fitting a member into the groove to hold theblade in place.

3. The method of claim 2, further including the steps A. placing apreliminary blade and said member into the groove,

B. machining the wall of the mold in which the blade is located to finaldimensions,

C. removing the member and preliminary blade from the groove,

D. making a new blade of the desired lateral dimension using thepreliminary blade as a model and E. inserting the new blade and themember into the OOVO gr k i

1. A method of making the heel of a shoe comprising the steps of A.providing a mold having a cavity configured to produce the heel andincluding a curved vertically extending wall, B. inserting and fixinghorizontally extending very thin blades in the curved verticallyextending wall of the cavity, said blades following the curvature of thewall being vertically spaced and projecting into the cavity a smallamount, C. placing a preformed covering material against the curvedvertically extending wall of the cavity and abutting a continuous extentof both the upper edge and the lower edge of the material against theblades so as to be held in position thereby, D. injecting a plasticmaterial into the cavity of the mold to press the preformed coveringmateriAl against the wall of the mold and to bond with the plastic, E.permitting the plastic material to harden and bond to the preformedcover and F. removing the injected molded heel with its cover from themold.
 2. The method of claim 1, in which the step of inserting andfixing the very thin blades in the mold includes A. forming a groove inthe vertically extending wall of the cavity, B. placing a said blade inthe groove and against the bottom side wall of the groove and C. snuglyfitting a member into the groove to hold the blade in place.
 3. Themethod of claim 2, further including the steps of A. placing apreliminary blade and said member into the groove, B. machining the wallof the mold in which the blade is located to final dimensions, C.removing the member and preliminary blade from the groove, D. making anew blade of the desired lateral dimension using the preliminary bladeas a model and E. inserting the new blade and the member into thegroove.